Following the enormous success achieved by bionic ears in returning hearing to profoundly deaf people, interest has now turned to developing a bionic eye that will return sight to the blind.
The eye operates by focusing light onto the retina which in turn passes signals to the brain, via the optic nerve, where they are processed to provide sight. Partial or total blindness can be caused by damage or malfunction of any of the elements in the chain from eye to brain. However, many common forms of blindness results from damage to the retina, for instance macular degeneration leads to deterioration in the cells of the fovea, causing a blind spot in the centre of the field of vision; but leaving the peripheral vision intact. The idea behind the bionic eye is to artificially stimulate the retina using an electrode array implanted on top of it. Other visual aids, such as vision spectacles stimulate the retina using light but control the images presented before the user.